MAPREDUCE-5999. Fix dead link in InputFormat javadoc (Akira AJISAKA via aw)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1618005 13f79535-47bb-0310-9956-ffa450edef68
MAPREDUCE-5906. Inconsistent configuration in property "mapreduce.reduce.shuffle.input.buffer.percent" (Akira AJISAKA via aw)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1618008 13f79535-47bb-0310-9956-ffa450edef68